A straightforward guide to units of time and their relation to each other

Author

Tess Loucka

Published

October 20, 2023

A straightforward guide to units of time and their relation to each other

Author

Tess Loucka

Published

Oct 11, 2023

A straightforward guide to units of time and their relation to each other

Author

Tess Loucka

Published

October 11, 2023

Key takeaways

- Units of time are the numerical values we use to measure time.
- When converting a larger unit of time to a smaller unit, multiply. When converting a smaller unit to a larger unit, divide.
- Months are standardized to all have 30 days in time-conversion problems.

Have you ever wondered how old you are? I mean, how old you are really? How many weeks, days, hours, minutes, and seconds old you are?

Knowing how to convert units of time is essential for answering questions like how old you are down to the day. It also comes in handy when marking your calendar for a date in the future or simply reading a clock to tell the time.

**Converting units of time** is one math topic that you’ll use every day throughout your life! So, what exactly is a unit of time anyway?

A unit of time a numerical value we use to measure time. Units of time include seconds, minutes, hours, days, weeks, months, and years.

When thinking about **how many seconds in a minute**, or **how many seconds in an hour**, what you’re really thinking about are time unit conversions.

Before we get into unit conversion, let’s go over the values of each unit of time.

- 1 minute = 60 seconds
- 1 hour = 60 minutes
- 1 day = 24 hours
- 1 week = 7 days
- 1 month = 30 days
- 1 year = 12 months
- 1 year = 365 days

You may be wondering why we say one month is equal to 30 days when we know that’s not always true. For the purpose of standardization, months are said to be 30 days long when calculating time conversion.

Additionally, even though some years are leap years that contain one additional day, we always treat one year as equal to 365 days during time unit conversions.

A general rule of thumb for time conversion is to multiply when converting a larger unit to a smaller unit and divide when converting a smaller unit to a larger unit.

For instance, to convert 1 hour into minutes, you’d multiply by 60 because there are 60 minutes in an hour. For example, if we want to know how many minutes are in 3 hours, we’d follow this formula:

3 x 60 = 120 minutes

On the contrary, to convert minutes into hours, you’d divide the amount of minutes by 60.

Try this!

How many hours are in 420 minutes?

To solve this problem, all we need to do is divide 420 by 60.

420 / 60 = 7

So there are 7 hours in 420 minutes.

Another thing to remember is that time on a clock always revolves around the number 60. There are 60 seconds and 60 minutes on a clock face, so when we convert seconds to minutes or minutes to hours, we’ll use the number 60 quite a bit.

To convert seconds to minutes, remember two key things:

- There are 60 seconds in 1 minute. Always use the number 60 when converting seconds to minutes.
- We are going from a smaller unit of time to a larger unit of time; therefore, we divide!

Ex. Convert 100 **seconds to minutes**. Divide 100 by 60. Sixty goes into 100 one time. The remainder is 40. So, 100 seconds is equal to 1 minute and 40 seconds.

To convert seconds to minutes, remember two key things:

- There are 60 seconds in 1 minute. Always use the number 60 when converting seconds to minutes.
- We are going from a smaller unit of time to a larger unit of time; therefore, we divide!

Ex. Convert 100 **seconds to minutes**. Divide 100 by 60. Sixty goes into 100 one time. The remainder is 40. So, 100 seconds is equal to 1 minute and 40 seconds.

Two tips to remember:

- 60 minutes = 1 hour
- We are going from a smaller unit of time to a larger unit of time, so we have to divide!

Ex. Convert 240 **minutes to hours**. Divide 240 by 60 to get 4. That means 4 hours equals 240 minutes.

Two tips to remember:

- 1 hour = 60 minutes
- We are going from a larger unit of time to a smaller unit of time, so multiply!

**hours to minutes**. Multiply 2 by 60 to get 120. Add 30 minutes. 120+30=150. There are 150 minutes in two and a half hours.

Two tips to remember:

- 24 hours = 1 day
- We are going from a smaller unit of time to a larger unit of time, so we have to divide!

**hours to days**. Divide 28 by 24. Twenty-four goes into 28 one time. The remainder is 4. So, there is 1 day and 4 hours in 28 hours.

Two tips to remember:

- 1 day = 24 hours
- We are going from a larger unit of time to a smaller unit of time, so multiply!

Ex. Convert 7 days to hours. Multiply 7 by 24 to get 168. That means 168 hours equals 7 days.

Two tips to remember:

- 7 days = 1 week
- We are going from a smaller unit of time to a larger unit of time, so we have to divide!

Ex. Convert 35 days to weeks. Thirty-five divided by 7 is 5. That means 5 weeks equals 35 days.

Two tips to remember:

- 1 week = 7 days
- We are going from a larger unit of time to a smaller unit of time, so multiply!

Ex. Convert 2 weeks and 3 days into days. Two multiplied by 7 is 14. Add 3 to get 17. There are 17 days in 2 weeks and 3 days.

Two tips to remember:

- 4 weeks = 1 month
- We are going from a smaller unit of time to a larger unit of time, so we have to divide!

Ex. Convert 6 weeks to months. Six divided by 4 is 1 with a remainder of 2. So, there is 1 month and 2 weeks in 6 weeks.

Two tips to remember:

- 1 month = 4 weeks
- We are going from a larger unit of time to a smaller unit of time, so multiply!

Ex. Convert 8 months to weeks. Eight multiplied by 4 is 32. So, there are 32 weeks in 8 months.

Two tips to remember:

- 12 months = 1 year
- We are going from a smaller unit of time to a larger unit of time, so we have to divide!

Ex. Convert 24 months to years. Twenty-four divided by 12 is 2. That means 2 years equals 24 months.

Two tips to remember:

- 1 year = 12 months
- We are going from a larger unit of time to a smaller unit of time, so multiply!

Ex. Convert 10 years to months. Multiply 10 by 12 to get 120. That means 120 months equals 10 years.

By now, we’ve gone over the rules for converting consecutive units of time, like minutes to seconds, or months to years. But what about non-consecutive conversion? How do you convert minutes to months? Or seconds to hours?

To convert non-consecutive units, start with the larger unit and work your way down to the smaller unit. Breaking the problem down into smaller problems helps us!

Let’s try turning one week into seconds:

Start by converting 1 week into hours. Since we are going from a larger unit of time to a smaller unit of time, we multiply:

1 week = 7 days

1 day = 24 hours

Therefore, we multiply 7 x 24 to get 168 hours in one week.

Next, let’s convert 168 hours into minutes. Once again, we are going from large to small so we multiply.

1 hour = 60 minutes

Therefore, we multiply 60 minutes by 168 hours to get 10,080 minutes.

For the last step, convert 10,080 minutes into seconds. You guessed it! We multiply again

1 minute = 60 seconds

Multiply 60 seconds by 10,080 minutes to get 604,800 seconds.

In other words:

7 days x 24 hours = 168 hours

168 hours x 60 minutes = 10,080 minutes

10,080 minutes x 60 seconds = 604,800 seconds

So, there are 604,800 seconds in 1 week.

Question 1: How many minutes are there in a week?

Answer: 10,080

Start with the largest unit of time and work down to the smallest. There are 7 days in one week. Each day, there are 24 hours. In each hour there are 60 minutes. 7x24x60=10,080.

Question 2: Convert 2 hours and 15 minutes into seconds.

Answer: 8,100

Start with the largest unit of time and work down to the smallest. In 1 hour, there are 60 minutes. That means 2 hours equals 120 minutes. Add 15 minutes to that to get 135 minutes. There are 60 seconds in each minute. 135×60=8,100.

Question 3: How many days are in 1 year, 2 months, and 11 days?

Answer: 436

Start with the largest unit of time and work down to the smallest. In 1 year, there are 365 days. Every month counts as 30 days, so 2 months equals 60 days. 365+60=425. Add 11 days to that to get 436.

Seconds, minutes, hours, days, weeks, months, and years.

The zeptosecond. A zeptosecond is a trillionth of a billionth of a second. However, the second is the smallest unit of time we use on a daily basis.

There are 60 minutes in an hour, so to convert hours to minutes, multiply by 60. When converting minutes to hours, you divide.

Lesson credits

Tess Loucka

Tess Loucka discovered her passion for writing in high school and has not stopped writing since. Combined with her love of numbers, she became a math and English tutor, focusing on middle- and high-school-level topics. Since graduating from Hunter College, her goal has been to use her writing to spread knowledge and the joy of learning to readers of all ages.

Tess Loucka

Tess Loucka discovered her passion for writing in high school and has not stopped writing since. Combined with her love of numbers, she became a math and English tutor, focusing on middle- and high-school-level topics. Since graduating from Hunter College, her goal has been to use her writing to spread knowledge and the joy of learning to readers of all ages.

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